Manufacture of fertilizer.



' To all whom it may concern:

. may be said to bea con lomerate of phos? phate and carbonate of lime witha portion 2 thus bringing them into. acondition wherein Y The said invention consists, first, in an: improved process of treating the send minable as fertilizing -n'iaterials, are inecl'mni rally mixed in predetermined proportions bined with said carbonate,"an'd a portion;

cial vald'e based on the percentages'of phos- LEONARD ROBERTS commas, or BALTIMORE, MARYLAND.-

MANUFAGT URE or FERTILIZER.

No Drawing. 7

Specification of Letters Patent Application filed August 26, 1909. Serial No. 514,686

" Be it known that I, LEONARD ROBERTS COATES,'Ofl3l1e city of Baltimore and State of Maryland, have invented certain Im provements in the Manufacture of -Fertilizers, of which the following is a specification. Y

This invention relates to a novel method of treating a certain mineral discovered by me, whereby the sameis rendered available for fertilizing purposes. The said inineralof the phosphate of lime chemically comgenerally' consisting of phosphatic fossils, mechanically mixed with the carbonate of lime; and the object of the said invention is to disaslsociate' certain of the said salts, and

they are adapted as agents in theapromotion" of plant life, as will hereinafter fully appear.

eral whereb the same is rendered an available plant cod and that without respect to the proportions of its constituent parts; and secondly, in an extension of the first process whereby the said salts .after being brought into the condition in which they arc-avail- :md so producea fertilizer having a commerphoric acid and lime contained therein.

In carrying out the first part of the process, I burn the mineral in order that the carbonate-"will be reduced to the oxid-of lime. In practice I find that in the burning, a temperature of 800 to 1500 C. is necessary to decompose the mineral and liberate the carbonic acid. In general it may be said; that thehigher the phosphoric acid content, the more heat will be required. The requisite heat is much higher tha'm the temperature necessary to decompose carbonate of lime and is probably due to the' fact that some of the phosphate present is combined chemically with the carbonate. I, then slake burned mineral by exposure to -'the* air -or cally combined with thccarbonate, broughtto a friable condition without material change in "shape and size. The material treated as described, will then consist of a mechanical mixture of hydrated lime, phosphate" of limein a finely divided state and phos hate of lime in coarse friable particles, and t e said salts not being'uniformly mixed,

the substance is not reliable commercially, -for general application to soils.

I therefore pass the material through a screen of suitable mesh, and the coarser particles which are screened out and consisting lar elyof phosphate of lime, are ground and ad ed to the'portion that has passedthrough the screen, after-which the wholeis thor.-..

Patented Oct. 4,1910.

oughly mixed. Thematerialw'ill then consist of' a mixture uniform throughout, 'of hydrated lime and phosphate of lime; and as the proportions of the elements of the crude material are not constant, but vary considerably, it will be understood that the I substanceproduced as described, 'while V3111."

able as a fertilizer, is not, for the reasons stated, in a condition to be sold as acornmercial article having a fixed value. I therea fore extend the process of manufacture in accordance with the second part of the in vention as follows: After the mineral is burned, slaked and screened, the coarserpartlcles ground, and the value of each of-the separated bodies ascertained, the same are.

again united :uul'in such proportions as are required to produce'a compound having a prcdoternnned value based upon the percentagcs of the lime and phosphoric acid contained therein.

' I am of the opinion based upon practical tests that phosphate of lime when brought to an impalpable powder by burning and slaking a limestone containing it, is as available for plant food, as phosphate rock after the phosphorus in the same is rendered soluble by means of sulfuric acid; and I am not aware that heretofore, that is to say,before my present invention, the mineral above referred to has been subjected to'any process.

looking to its adaptation as a fertilizing agent. Y

I therefore claim as my invcntion,

,1. The process of producing from a, mineral consisting of a conglomerate of carbonate of lime and phosphate oflime chem-.

ically combined, and the same mechanically mixed with carbonate of lime, and phosphatic fossils, two separate bodies adapted for fertilizing purposes, but differing in agricultural and commercialyalues, one body consisting of hydrate of lime mechanically mixed with a phosphate otli'me, both salts being in the condition of practically impalpablei powder, and the other body, of

phosphate of lime in fossil tor'm and a friable condition, which consists in burning and slaking the said material, and then separating the same into two bodies by screen-' ing out the said friable fossils of phosphate of lime, substantially as specified.

2. The process of treating a mineral composed of carbonate of lime-and phos hate of lime which are in chemical combination, and the same mechanically mixed with phosphate of lime, whereby the two salts are disassociated and the latter reduced to practically an iinpalpable powder, and the whole brought to a body having the same constituent parts distributed throughout in uniform proportions, which consists in burning,

. and slaking the mineral, then screening out the coarser particles of phosphate of lime and grinding them, and then returning the ground to the unground constituent and mixing the two bodies together, substantially as, and for the purpose specified. 3. The process or treating a mineral composed of carbonate of lime and phosphate of lime which are in chemical combination andthe same mechanically mixed with phosphate of lime, whereby the two salts are disasso-.

ciatcd and the latter reduced to a practically impalpable powder, and a body thereby produced having the said constituent parts mechanically combined in predetermined proportions, which consists in burning and slaking the mineral, then screenin out the coarser particles of phosphate of e, and

then mixing the ground and unground salts together in predetermined proportions whereby a fertilizer is produced having a commercial value based on the proportions of phosphoric acid-and lime, contained therein, substantially as, and for the purpose specified.

LEONARD ROBERTS GOATES.

. \Vitnesses:

WM. T. Hou ann, EDWARD P. HILL. 

